One central tenet of personalized medicine is to be able to predict who is at risk for later medical conditions, including mental illness (NIH, 2007). To transform our knowledge of the origins, mechanisms, and processes that contribute to later dysfunction, the National Advisory Mental Health Council (2007) has called for increased longitudinal, trajectory-based studies that include sensitive, malleable periods of neurodevelopment to meet Objectives 1 and 2 of the new NIMH Strategic Plan. With recent methodological advances that have shed light on developmental pathways toward childhood psychopathology, there is a pressing need reflected in PA07-158 to identify specific precursors to improve early identification and intervention. Executive control (EC) is a strong candidate precursor for childhood externalizing disorders (including ADHD), although two challenges have hampered progress: 1) lack of a precise definition of EC and 2) inadequate understanding of how EC contributes to later functional outcomes. In this past funding period, we have made substantial progress in defining EC in preschool children by using sophisticated statistical methods to empirically determine the best fitting, theoretically derived model. The objective of this renewal application, then, is to elucidate how precursor EC relates to later functional outcome, the next translational step towards clinical application. Participants will be the large, carefully, longitudinally (every 9 months, 3-0 to 5-3 years) sampled preschool cohort (half are at sociodemographic risk) who will enter grades 1 or 2 in fall 2009-2011. Multi-method assessments of functional outcome in spring grades 1-4 will be conducted, focusing on externalizing problems (impulsivity/hyperactivity, inattention, defiance, and aggression), social skills (sensitivity, responsibility, and peer relationships), academic skills (mathematics and reading achievement), and mastery problems (poor motivation, persistence, strategy use). The cohort is on the cusp of a key 5->7 shift, the developmental transition characterized by a substantial increase in adult expectations for goal-directed thought, sustained independent work, adaptive relationships and social functioning. In this 5->7 shift, elementary school is the central context where these increased expectations challenge or press the child to deploy executive control to successfully manage this transition, a key factor in later functional success. Structural equation modeling will be used to test the a priori direct and meditation relations among preschool executive control, behavior in the 5->7 shift, and functional outcome. To pinpoint who is at greater risk for poor outcome, cutting-edge, person-centered growth mixture modeling will be conducted to identify latent subgroups of preschool children with poor EC development and then to compare later functional outcome and examine the contribution of responsive parenting. Characterizing the nature of executive control in the preschool period and how it relates to trajectories of later functional outcome will elucidate the fundamental mechanisms that go awry in childhood psychopathology and identify precursors for use in future work to tailor preventive interventions to those who stand to benefit most. PUBLIC HEALTH RELEVANCE: Identifying early precursors in pathways to later dysfunction is critical to enhance preventive interventions in the longer term. Executive control plays a fundamental, and perhaps causal, role in externalizing problems and related adverse social and academic outcomes, and therefore is a strong candidate for translational use in early identification. Understanding the longitudinal relations of preschool executive control and functional outcome in grades 1-4, and characterizing putative mechanisms in a large, well-characterized cohort who range in sociodemographic risk, will elucidate important developmental pathways towards psychopathology.